Box erecting devices for reducing the effect of stringing out of adhesives



May 12, 1970 'r. R. BAKER 3,511,138

BOX ERECTING DEVICES FOR REDUCING THE EFFECT OF STRINGING OUT OFADHESIVES Filed April 20, 1967 '7 Sheets-Sheet 1 I NVENT 0R.

Thomas R. Baker 4.; ATTORNEY May 12, 1970 T. R. BAKER 3,511,138

BOX ERECTING DEVICES FOR REDUCING THE EFFECT OF STRINGING OUT OFADHESIVES Filed April 20, 1967 7 Sheets-Sheet 2 INVENTOR. Tho/has A.Baker 1 A TTO/P/VEY May 12, 1970 T. R. BAKER 3,511,133

BOX ERECTING DEVICES FOR REDUCING THE EFFECT OF STRINGING OUT OFADHESIVES '7 Sheets-Sheet 5 Filed April 20, 1967 SEE! BEIGE DUDE]CHIHIIU INVENTOR. Thomas R. Baker ATTORNEY May 12, 1970 -T. R. BAKER3,511,133

BOX ERECTING DEVICES FOR REDUCING THE EFFECT OF STRINGING OUT OFADHESIVES Filed April 20, 1967 7 Sheets-Sheet 4 I NVENTOR. Thomas 1?.Baker a). A TTORNEY 'r. R. BAKER 3,511,138

May 12, 1970 BOX ERECTING DEVICES FOR REDUCING THE EFFECT OF STRINGINGOUT OF ADHESIVES 7 Sheets-Sheet 5 Filed April 20, 1967 EDGE SUEZ] DEED[BLISS DUDE DUDE] mama BED INVENTOR. Thomas R Baker 4;, A TTOR/VEY May12 1970 T. R. BA KER BOX ERECTING DEVICES FOR REDUCING THE EFFECT OFFiled April 20, 1967 STRINGING OUT OF ADHESIVES '7 Sheets-Sheet 6INVENTOR. 7720mm 1?. Baker BY (f-014M W aw. A TTOR/VEY Fig. 6

May 12, 1970 'r. R. BAKER BOX ERECTING DEVICES FOR REDUCING THE EFFECTOF" STRINGING OUT OF ADHESIVES '7 Sheets-Sheet 7 Filed April 20, 196759% 55 Pa .5 s i i 5 Ii INVENTOR. Thomas R. Baker I ATTORME)" UnitedStates Patent O BOX ERECTING DEVICES FOR REDUCING THE EFFECT OFSTRINGING OUT OF ADHESIVES Thomas R. Baker, Los Altos, Califi, assignorto Kliklok Corporation, New York, N.Y., a corporation of Delaware FiledApr. 20, 1967, Ser. No. 632,291 Int. Cl. B31b 1/44 U.S. Cl. 93-51 2Claims ABSTRACT OF THE DISCLOSURE In an adhesive applicator of the typein which a nozzle deposits a bead or line of adhesive on paperboard andthe like, uncontrolled deposition of a thread of adhesive strung outfrom the nozzle is avoided by depositing such strung-out adhesive on thepreviously deposited bead or line of adhesive.

BACKGROUND OF THE INVENTION Field of the invention Liquid adhesivedischarged in the form of a bead or line from a nozzle or orifice tendsto string out in the form of a thin thread after the flow of adhesiveceases.

This phenomenon is referred to as stringing-out in the paper boxindustry and is objectionable as it is unsightly and may produce anadhesive bond between areas of a folding box where no bond is desired.

Description of the prior art In the use of roller type adhesiveapplicators it is known to counteract the effect of string-out by theuse of a further roller so placed as to catch and wind up the adhesivethread or string before it falls on the board.

However, where nozzles are used for depositing, by extrusion rather thanspraying, a line or bead of adhesive wind-up rollers cannot be installedfor various reasons, one of the principal reasons being lack of space.

Stringing out of adhesive can be reduced to some extent by nozzlescomprising a built in shutoff valve so placed as to leave only anextremely small volume of adhesive available downstream of the shutofipoint for stringing out. But as this volume cannot be reduced to zero, astring-out problem continues to exist.

SUMMARY OF THE INVENTION The present invention proceeds from theprinciple of rendering harmless the string-out which cannot be preventedby depositing the strung-out thread on the previously deposited adhesiveline or bead.

This is particularly desirable and advantageous where the line or beadof deposited adhesive must be short and be localized to produceaccurately defined glue spots.

The objects, features and advantages of this invention will appear morefully from the detailed description which followsaccompanied by drawingsshowing, for the purpose of illustration, a preferred embodiment of theinvention. The invention also resides in certain new and originalfeatures of construction and combination of elements, as well as stepsand sequences of steps hereinatfer set forth and claimed.

Although the characteristic features of this invention which arebelieved to be novel will be particularly pointed out in the claimsappended hereto, the invention itself, its objects and advantages and amanner in which it may be carried out may be better understood byreferring to the following description taken in connection with theaccompanying drawings.

3,511,138 Patented May 12, 1970 FIG. 1 is a perspective View of theadhesive applying and box forming portion of a box forming machineillustrating the instant of delivery of a flat box blank;

FIGS. 2 to 5 are sequential views illustrating the operation of theadhesive applying mechanism of the machine;

FIG. 6 is a perspective view of a portion of the mechanism for movingthe applicator nozzles;

FIG. 7 is a perspective view of the adhesive supply reservoir andadhesive feeding mechanism; and

FIG. 8 is a sectional view of a typical construction of an adhesiveapplying nozzle used in the device.

In the following description and in the claims various details will beidentified by specific names for convenience. The names, however, areintended to be generic in their application. Corresponding referencecharacters refer to corresponding parts in the several figures of thedrawings.

The drawings accompanying, and forming part of, this specificationdisclose certain specific details of construction for the purpose ofexplanation of broader aspects of the invention, but it should beunderstood that structural details may be modified in various respectswithout departure from the principles of the invention and that theinvention may be incorporated in other structural forms than shown.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a blankfeeding mechanism 11 of known construction comprising suction cups 12 isseen carrying a flat box blank B for deposit above a box forming die 13.

The die aperture is bounded by four angularly bent plates, of whichplates 14 and 15 are designed to fold the box front and rear panel intoupright position. Plates 16 and 17 serve to fold the box end wall panelsinto upright position.

The end panel folding plates 16 and 17 comprise horizontal portions 18and 19 on which the end wall panels come to rest when the blank B isdeposited by the feeder cups 12 (see FIGS. 2 and 3).

The die assembly further comprises corner flap folding elements 20, oneat each die corner, for engaging and upwardly folding corner flaps 21 ofthe blank B. The folding elements 20 also comprise projecting edges 22underneath which the edges of folded corner flaps snap, thus trappingthe prefolded blank in position above the die aperture when the blankfeeder withdraws (FIG. 3).

Details of the blank construction are best seen in FIG. 4. The blankcomprises a bottom panel 23, front and rear wall panels 24, 25,respectively, end panels 26, 27, a cover panel 28 and a front flap 29 onthe latter. The previously mentioned corner flaps 21 extend laterallyfrom the front and rear box body panels 24 and 25, respectively, and itis one purpose of the box assembly procedure adhesively to secure thecorner flaps 21 to the end wall panels 26, 27 by means of adhesiveapplied to the end wall panel within predetermined areas.

Two adhesive applicators 30- and 31 are provided for this purpose, eachcomprising a manifold housing 32 from which several applicator nozzles33 project downwardly towards a blank resting on the horizontal plateportions 18, '19. Molten adhesive is supplied to the manifolds 32through heated flexible ducts 34 from a melting pct 35 at the rear ofthe machine (FIG. 7) via an appropriate periodically operated feed pump.

Returning to FIGS. 1-3, the adhesive applicators are mounted forreciprocating motion towards and away from the die aperture 13 in aplane substantially parallel to the horizontal plate portions 18, 19.

For this purpose the applicators are mounted on mounting plates 36, 37,the far ends of which move in horizontal guideways, of which one isvisible at 38 (FIG. 1). The near portions of the plates are secured tosleeves 39, 40 slidable on a rod which is barely visible at 41 behindthe machine frame.

A bell crank lever 42 pivotally mounted at 43 engages the right sleeve39 at 44. A bolt 45 extends downwardly from the sleeve 39 to a push rod46 articulated to a doublearmed lever 47 at 48. The lever 47 is pivotedto the machine frame at 49, and a further push rod (not visible) extendsfrom the other arm of the lever 47 to a similar pin on the sleeve 40which for this reason moves in a direction opposite to the sleeve 39.

Helical springs '50, 51, best seen in FIG. 3, tend to urge the sleeves39, 40 toward each other, thereby eliminating lost motion in theoperating linkage, and further serve to maintain a cam follower 52against a drive cam 53 shown in FIG. 6. The cam 53 is fastened on adrive shaft or driven shaft 54 of the machine. The follower roller 52 ismounted on one arm of a double armed oscillating lever '55 from theother arm of Which a push rod 56 extends to the second arm of the bellcrank lever 42 projecting through an aperture 57 in the machine frame.

In order to facilitate the understanding of the adhesive applicatormotion, a marker 58 was afiixed to the machine frame in a location flushwith the end of the sleeve 39 in the position in which the applicatorsare fully retracted (FIG. 1). Immediately after deposition of the blank,the adhesive applicators 30, 31 begin to move towards each other (FIG.2) and While so moving the adhesive feed pump is operated causing astream of adhesive to be discharged from the nozzles 33 of theapplicators.

Depending on whether the duration of discharge is brief or longer, abead or a line of adhesive is being deposited at 59 on the end wallpanels 26, 27 of the deposited blank.

In the position shown in FIG. 3, the applicators have approached eachother to the maximum extent (compare the position of the end of thesleeve 39 with the marker 58) and the deposition of adhesive iscompleteexcept for the stringing out of the last portion of thedischarged adhesive which is likely to form a tacky thread from thedeposit bead or line 59 to the nozzle proper.

In FIG. 4 the applicators 30, 31 are shown to retract in order to clearthe descending box forming plunger 60 which is about to drive the blankinto the die throat (FIG.

As the applicators move away from each other the tacky string ofadhesive falls on the previously applied adhesive bead or line.

The corner flaps are then folded inwardly of the end panels and anadhesive bond is formed between the corner flaps and the end walls bythe applied adhesive.

Referring to FIG. 7, the adhesive feed pump 61 is mounted underneath themelting pot 35. A terminal fitting of the heated adhesive duct can beseen entering the pump housing at 62'. The pump 61 powered by apneumatic servo-motor 62, the servo-motor being controlled by asolenoid-operated control valve. The control valve, in turn, is operatedby a cam-controlled microswitch 63.

The control cam 64 is composed of two cam discs, each having a highportion and a low portion. By rotation of the discs relatively to eachother the duration of actuation of the switch may be varied, and thediscs are then fixed relatively to each other by clamping bolts 65.Suffice it to say that the switch 63 is actuated while its roller 66engages the cam between markers 67.

A representative form of nozzle is shown in FIG. 8. It comprises aneedle type valve element 68 which opens and closes a discharge aperture69 in the nozzle housing 70. A helical spring 71 hearing against aflange '72 on the element 68 tends to maintain the valve element 68 inits closing position. Adhesive under pressure entering at 73 acts on theunderside of the flange 72 and opens the valve when the pressure issuflicient to overcome the force of the spring which may be varied 'bymeans of a nut 74.

What is claimed is:

1. In a box erecting device comprising a die; transport means fordepositing a flat folding box blank over the mouth of the die; ahot-melt adhesive applicator comprising a source of hot-melt adhesive, adischarge nozzle comprising a pressure-responsive valve means foropening the valve at a pressure above, and closing the valve at apressure of the supplied adhesive below, a preset pressure limit,respectively, and a nozzle carrier for supporting said nozzle forreciprocating movement in a direction towards, and away from, the axisof the die, respectively, to extend during its forward stroke over aportion of a blank deposited on the mouth of the die and to withdrawfrom above said portion during the return stroke; a plunger movable intoand out of the die for pressing said blank into the die and folding saidblank portion toward a side surface of the plunger; and a pump operablein timed relationship with the plunger movement for periodically feedingmolten adhesive under pressure to said nozzle, the improvementcharacterized by an actuating mechanism for said pump so timed as tocause adhesive under pressure to be fed to said nozzle exclusivelyduring the forward stroke of said nozzle carrier,

, whereby filament of adhesive strung out after closure of said valvemeans and during the return stroke of said carrier is caused to settleon, and to be captured by, the liquid adhesive previously deposited bysaid nozzle during the forward stroke of the carrier.

2. The device defined in claim 1 in which said blank portion is a boxwall panel, in which the nozzle carrier moves in a directionsubstantially normal to the surface of the plunger against which surfacesaid panel is to be folded, and in which said pump is being actuated todeliver adhesive under pressure during only a fraction of the forwardstroke of the carrier.

References Cited UNITED STATES PATENTS 6/1949 Curlee 118-25 2/1969Wagner 118-411 X US. Cl. X.R.

